Air trap for liquid pressure lines



May 3, 1932. w, MARDEN 1,856,105

AIR TRAP FOR LIQUID PRESSURE LINES Filed Sept. 6, 1930 INVENTOR ll i'lllam Ljlwrdall,

BY I 02147? ATTORNEY/5 llflthlflljlfilhl', 01ft ELIMHUREH', YORK, ASSIGNUR T0 NEPTUNE METER GOM- lPAhl'Y, NEW YORK, N. "521, A CORPORATIUN OF NEW JERSEY .lClEtAlP FUR lh'lIQUID PRESSURE lLIIhTlES .l'tpnlicatien fiIed September T he present invention relates to air releasmechanism for gasoline dispensing apparatus and embodies, more specifically, an improved air trap and release for gasoline measuring and dispensing equipment wherein high pressures are utilized in directing the flow of the gasoline.

More particularly, the invention relates to whatmight be termed a servo-valve mechanism for equipment of the above character wherein the etl' ect ot' the pressure of the fluid upon the air releasing mechanism is negligible in so tar as the functioning of the device is concerned. There have been provided many terms of mechanism for separating a gas from a liquid and the forms of such mechanisms have uniformly included either a balanced valve or a float actuated valve which is designed to close the air vent when the liquid level rises above a predetermined amount. Where the fluid is handled under low pressures, these forms of devices are satisfactory inasmuch as they effect the separation of the gas from the liquid' It has been found, however, that such devices are unsatisfactory where the liquid and gas are handled under high pressures. Such pressures operate directly against the valve to maintain the same closed regardless of the tloat. The float thus is ineffective to operate the valve when the fluid is under high pres sure and merely is held in a fixed position by the pressure upon the valve regardless of the liquid level in the float chamber. Where the fluid involved is of a low specific gravity, the weight of the float cannot be made sufficiently great to overcome the pressure of the tluid upon the valve nor can the size of the float be made very great without danger of collapseunder the high pressures involved.

The present invention therefore seeks to provide a device for separating a gas from a liquid regardless of the pressure under which the system is operatin In this connection, it will be readily apparent that the mechanism may be used in a Wide range of service other than that of gasoline dispensing equipment as described herein.

A further object of the invention is to pro vide a power operating device for separating gas from a liquid, the power utilized being 6, 1930. Serial No. dbEWG'Y.

the combination of atmospheric pressure upon a suitable device with the pressure available in the system.

A further object of the invention is to provide a servo valve mechanism for operating a device of the above character.

Further objects of the invention, not specilically enumerated above, will be apparent as it is described in further detail in connection with the accompanying drawing, the single figure of which is a View in vertical section, taken through a device constructed in accordance with the present invention.

Referring to the drawing, a separating chamber is indicated at a, being provided with a supply pipe a and a discharge pipe a In the suggested form, a cover plate a is secured to the housing a by means of bolts a and is formed with a valve aperture a. This valve aperture is provided with a valve seat a which cooperates with a movable valve member a having an extension a which projects Within the housing and is subject to the pressure existing therein. I

An auxiliary housing b is secured to the cover plate a by means of bolts 6, this housing being formed with a bellows chamber 6 and having an air vent communicating therewith. The bellows chamber communicates with the valve passage a and contains a belows 0 which is secured to a base plate a and carries a plate 0 upon which the valve a7 is mounted.

The upper extremity of the auxiliary housing is formed with a recess 0 which communicates with an aperture 0 formed in the base plate 0 and a passage 0 which is drilled in the upper wall of the auxiliary housing. The outer extremity of the passage is closed by means of a screw 0.

lVithin the auxiliary housing I), a second chamber a is formed, this chamber communicating with the interior of the housing a through an aperture a formed in the cover plate a A spider c is threaded into the lower extremity of the chamber 0 and serves as a spacer for a valve rod (Z, described in further detail hereinafter.

A passage 0 is drilled in the top of the housing 6 and is provided with a valve seat 0 The upper extremity of chamber 0 is restricted at 0 and receives a valve seat 0 the valve seat being formed with an axial passage 0 through which a valve rod d passes.

The upper extremity of valve rod (Z is formed with an oppositely tapered valve head (1 which is adapted to cooperate with the valve seats 0 and 0. Upon the lower extremity of the rod (Z, a flanged collar 01 is secured, the collar receiving the arms of a bifurcated lever e which is secured to a float arm e. The float arm 6 is pivoted at 6 upon an arm 6 secured to the auxiliary housing I; and carries a float e which is adapted to rise and fall with the liquid level within the housmg a.

From the foregoing description, it will be seen that air in the housing a may normally escape through the valve seat a into the chamber 6 and through the air vent 6 The valve 11 is maintained unseated by the pressure of the fluid within the chamber. WVhen the fluid level rises the float 6 will rise elevating the valve head d and eventually clos-- ing the communication afforded by passage 0 between the atmosphere and the passage 0 Atmospheric pressure will thus be relieved within the bellows o and the pressure of the fluid within the housing a will be applied to the bellows. Inasmuch as the area of the bellows is greater than the area of the valve port a", the diflerence in pressures upon the valve due thereto will tend to force the valve against its seat Under this condition, a slight bias on the bellows is desirable but not essential.

It will thus be seen that a valve mechanism has been provided which functions effectively to permit air to be separated from the liquid regardless of the pressure to which the liquid is subjected.

While the invention has been described with specific reference to the accompanying drawing, it is not to be limited, save as defined in the appended claims.

I claim as my invention:

lows and the atmosphere or first chamber selectively, and a float operated mechanism for controlling the last named valve.

This specification signed this 3rd day of September, A. D., 1930. 5 WILLIAM L. MARDEN.

1. A collecting chamber, a gas vent therein I communicating with an outlet, means to direct a flow of a liquid through the chamber, a valve for the vent, pressure responsive means to operate the valve, means to subject the pressure responsive means to the pressure of the outlet, means to subject the said means to the pressure within the chamber, and means responsive to the liquid level to control the two last named means.

2. A collecting chamber, a gas vent therein, means to direct a flow of a liquid through the chamber, a valve for the vent, pressure responsive means to operate the valve, said means having a normal bias tending to close the valve, means to subject the pressure responsive means to atmospheric pressure, means to subject the said means to the pressure within the chamber, and means respon- 

